1. Field of the Invention
This invention generally relates to hot beverage brewers, such a coffee or tea brewers, and more particularly, to an electrical hot beverage brewer
2. Discussion of the Prior Art
Electrical coffee or tea brewers or the like of the type that hold the beverage ingredient in a brew chamber for a preselected seeping time period and then quickly discharge the freshly brewed beverage out of the brew chamber are known.
Drip-type beverage brewers operate by filling a brew chamber with hot water that immediately begins to percolate through a layer of beverage ingredient and out of an open drain hole as soon as the first water is added until all the beverage has passed through the ingredient. The rate at which the beverage passes from the drain hole is dependent upon the rate at which the hot water is dispensed into the brew chamber and the level of beverage in the brew chamber. The rate is higher at the beginning of the period and slows to mere drips once the brew chamber is near empty. There is no seeping period during which all the hot water added remains in the brew chamber to form a uniformly extracted beverage before any of the beverage is released from the brew chamber. Accordingly, the brew chamber, or brew basket, need not have capacity to hold all the entire batch of beverage made during a single brew cycle. Disadvantageously, the extraction is uneven and difficult to control, with most of the extraction occurring during the beginning of the brew cycle
Another disadvantage is that commencement of a new brew cycle is delayed while waiting for the end of the drip period. Because the drain hole at the bottom of the brew basket is always open, it is necessary to wait until the last of the hot water has passed through the beverage ingredient within the brew chamber and drained out of the brew chamber before removing the brew chamber from the brewer for reloading. It is necessary to wait because failure to do so results in dangerous and unsanitary spillage of hot beverage on floors, counter tops and onto the operator's skin or clothing.
Espresso machines produce small amounts of beverage with very concentrated flavor in a single phase during which hot water under steam pressure is rapidly forced though a brew chamber containing the ground espresso coffee beans. However, suffer from an open drain brew chamber, and another disadvantage of such espresso machines is that they are generally suitable for making only a single small cup of espresso per brew cycle. Accordingly, it is known to increase the amount of beverage by mixing the finished espresso beverage with hot water to form what is known as an “Americano”.
In a French press-type brewer, larger quantities of beverage are brewed during a single phase in which a plunger directly engages and presses the layer of beverage ingredient in the brew chamber against the bottom filter support to rapidly press the beverage through the porous ingredient layer and out of the brew chamber after a preselected seeping period.
In press-type brewers, the drip period my be accelerated by means of direct pressing by the plunger, but residual liquid in the brew chamber can still drip out of the brew chamber after it is disconnected from the brewer. Another problem with known press-type brewers is caused by the plunger coming into direct, physical, intimate contact with the beverage and the wet beverage ingredient. In the event that different types of coffee or different flavored coffee are being successively brewed, then there can be flavor contamination from one batch to the next due to residual beverage and wet, spent beverage ingredient adhered to the plunger and associated parts immersed into the beverage and pressed against the layer of beverage ingredient. In order to avoid such contamination, it is necessary to wash clean the plunger between each batch of beverage being brewed. Disadvantageously, such cleaning of the plunger increases the length of time needed to properly prepare and load the brewer for the next brewing cycle.
This additional preparation time reduces the speed at which successive brew cycles may be performed and can thereby cause service delays in a commercial brewing operation, such as in a coffee house, tea room or catering environment. In such commercial operations it is often very important that each batch of freshly brewed beverage may be made as quickly as possible. In addition, the elimination of the step of washing eliminates the need and costs of water and detergent for the washing operation.
Another problem with the operation of known press-type brewers is that it is not possible for the brewer to make an amount of beverage during a single brew cycle that is greater than the maximum volume of beverage and hot water that can be held by the brew chamber. If a greater volume is required, then additional brew cycles are needed to make the greater volume. However, increasing the volume capacity of the brew chamber requires larger brewer parts and tends to make the brew chamber unwieldy to load, unload and otherwise handle. Again, in a commercial beverage operation, such delays and the resultant reduced volume through-put should be avoided as much as possible to obtain maximum efficiency. Also, control of the ratio of the volume of hot water to quantity of dry beverage ingredient and the length of brewing time is limited due to the maximum volume of the brew chamber.